Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation
Funding: UK Natural Environment Research Council (NERC) grant NE/N011716/1 (JWBR and AB). Tamaki Foundation, NASA (Grant NNX17AH56G), and NSF (Grant AGS-1929775) (RCJW). NERC Independent Research Fellowship NE/K008536/1 (RFI). North Pacific atmospheric and oceanic circulations are key missing pieces...
Published in: | Geophysical Research Letters |
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Main Authors: | , , , , , , , |
Other Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2021
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Subjects: | |
Online Access: | http://hdl.handle.net/10023/21638 https://doi.org/10.1029/2019GL086328 |
Summary: | Funding: UK Natural Environment Research Council (NERC) grant NE/N011716/1 (JWBR and AB). Tamaki Foundation, NASA (Grant NNX17AH56G), and NSF (Grant AGS-1929775) (RCJW). NERC Independent Research Fellowship NE/K008536/1 (RFI). North Pacific atmospheric and oceanic circulations are key missing pieces in our understanding of the reorganisation of the global climate system since the Last Glacial Maximum (LGM). Here, using a basin‐wide compilation of planktic foraminiferal δ18O, we show that the North Pacific subpolar gyre extended ~3° further south during the LGM, consistent with sea surface temperature and productivity proxy data. Climate models indicate that the expansion of the subpolar gyre was associated with a substantial gyre strengthening, and that these gyre circulation changes were driven by a southward shift of the mid‐latitude westerlies and increased wind‐stress from the polar easterlies. Using single‐forcing model runs, we show that these atmospheric circulation changes are a non‐linear response to ice‐sheet topography/albedo, and CO2. Our reconstruction indicates that the gyre boundary (and thus westerly winds) began to migrate northward at ~16.5 ka, driving changes in ocean heat transport, biogeochemistry, and North American hydroclimate. Publisher PDF Peer reviewed |
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